This invention relates generally to the field of lockout mechanisms for electrical protective devices, and more particularly to a lockout device for use with a ground fault circuit interrupter or an arc fault circuit interrupter.
Electrical protective devices such as ground fault circuit interrupters, arc fault circuit interrupters, circuit breakers, etc. are designed to trip when a fault condition occurs. The trip mechanism used to mechanically break the circuit connection between the input and output conductors typically includes a solenoid. A test button tests the circuitry and trip mechanism while a reset button is used to reset the electrical connection between the input and output conductors. In some devices, the device is capable of being reset even if internal components have failed.
Briefly stated, an electrical protective device that includes a reset mechanism uses a resistor body to act as a hold-off to a spring driven lockout for the reset mechanism. Upon the failure of an internal component of the protective device, the spring driven lockout mechanism is released by I2R thermal action which causes a resistor to burn in half, or in the alternative, to melt solder mounting the resistor, thereby eliminating the hold-off and locking out the reset mechanism.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a spring biasing the lockout; a resistor body which holds the lockout in a first position against action of the spring, wherein the first position permits resetting the electrical protective device; and a switch responsive to an internal fault in the electrical protective device, wherein activation of the switch sends a current through the resistor body; wherein when the resistor body reaches a predetermined temperature, the resistor body ceases to hold the lockout in the first position, whereby the lockout moves to a second position by action of the spring, and wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a resistor body which holds the lockout in a first position, wherein the first position permits resetting the electrical protective device; means, responsive to an internal fault in the electrical protective device, for sending a current through the resistor body; and means, responsive to the resistor body reaching a predetermined temperature, for moving the lockout to a second position, wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a reset mechanism which is biased by a reset spring; a lockout spring; a resistor body which holds the lockout spring in a first position against action of the lockout spring, wherein the first position permits resetting the electrical protective device; and a switch responsive to an internal fault in the electrical protective device, wherein activation of the switch sends a current through the resistor body; wherein when the resistor body reaches a predetermined temperature, the resistor body ceases to hold the lockout spring in the first position, whereby the lockout spring moves to a second position, and wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a method for locking out a reset mechanism of an electrical protective device includes the steps of providing a spring driven lockout for the reset mechanism; providing a resistor body which holds the lockout in a first position, wherein the first position permits resetting the electrical protective device; sending a current through the resistor body in response to an internal fault in the electrical protective device; and moving the lockout to a second position in response to the resistor body reaching a predetermined temperature, wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a spring biasing the lockout; a resistor body which holds the lockout in a first position against action of the spring, wherein the first position permits resetting the electrical protective device; and a current path responsive to an internal fault in the electrical protective device, wherein activation of the current path sends a current through the resistor body; wherein when the resistor body reaches a predetermined temperature, the resistor body ceases to hold the lockout in the first position, whereby the lockout moves to a second position by action of the spring, and wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a spring biasing against a resistor body, wherein an electrical current through the resistor body maintains lockout; the resistor body reaching a predetermined temperature when the current has sufficient energy from a duration or magnitude of the current; when the resistor body reaches the predetermined temperature, the biasing of the spring displaces the resistor body such that electrical current through the resistor body is interrupted, wherein the interruption permits resetting the reset mechanism.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a spring biasing the lockout; a resistor body which holds the lockout in a first position against action of the spring, wherein the first position permits resetting the electrical protective device; means for sending a current through the resistor body in response to an internal fault in the electrical protective device; wherein when the resistor body reaches a predetermined temperature, the resistor body ceases to hold the lockout in the first position, and the lockout moves to a second position by action of the spring; and wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a spring biasing the lockout; an electrical component which holds the lockout in a first position against action of the spring, wherein the first position permits resetting the electrical protective device; means for sending a current through the electrical component in response to an internal fault in the electrical protective device; wherein when the electrical component reaches a predetermined temperature, the electrical component ceases to hold the lockout in the first position, and the lockout moves to a second position by action of the spring; and wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a hold-off body which holds the lockout in a first position, wherein the first position permits resetting the electrical protective device, the hold-off body being affixed to a part of the electrical protective device with a compound having a melting point; an electrical component of the electrical protection device being adjacent the hold-off body; means, responsive to an internal fault in the electrical protective device, for sending a current through the electrical component; and means, responsive to the electrical component reaching the melting point of the compound, for moving the lockout to a second position, wherein the second position prevents resetting of the electrical protective device.
According to an embodiment of the invention, a lockout for a reset mechanism of an electrical protective device includes a resistor body which holds the lockout in a first position, wherein the first position prevents resetting the electrical protective device; means, responsive to correctly wiring a supply voltage to the electrical protective device, for sending a current through the resistor body; and means, responsive to the resistor body reaching a predetermined temperature, for moving the lockout to a second position, wherein the second position permits resetting of the electrical protective device.